Electric power generation plants, communication facilities, water supply facilities, airports, oil plant, and the like are important facilities in the urban foundation. When such important facilities fail to function, the adverse effect on the society is enormous. For this reason, it is required to strictly protect the important facilities. In one of methods for protecting the important facilities, a video analysis system is used to cause a computer to analyze video data captured by a monitoring camera, recognize moving objects (person, car, suspicious object, and the like) in the video, and monitor the flows of the moving objects (travelling direction, movement line, behavior, and the like). In general, in a video analysis system using a computer, a user defines an abnormal status in advance, so that the abnormal status defined from target video data is detected.
An example of such video analysis system using the computer is described in patent document 1 (Japanese Patent Application Laid-Open No. 2008-047074). It is an object of the invention described in patent document 1 to provide a guard apparatus, a guard method, and a guard program capable of determining a suspicious individual in an area where a family member or a visitor may be detected, and capable of giving warning to only the suspicious individual. The guard apparatus described in patent document 1 includes a behaving person detection unit, a detection area determination unit, a suspicious individual determination unit, a speaker, and an indicating lamp. The behaving person detection unit detects a behaving person on the basis of image information captured by the monitoring camera and reference image information stored in the reference image storage unit. The detection area determination unit determines which detection area of the detection areas the behaving person has been detected, on the basis of the behaving person detected by the behaving person detection unit and the detection area stored in the detection area data base. The suspicious individual determination unit determines whether the behaving person is the suspicious individual or not on the basis of the detection area detected by the detection area determination unit. A speaker and an indicating lamp notify existence of the suspicious individual in a case where the behaving person is determined to be the suspicious individual.